4. The World File

The world file is used to describe the particular set of robots,
sensors and objects to be simulated by Stage. Stage reads the world
file on start-up and creates entities as indicated in the file. Stage
may also write updated pose information into the world file when the
user selects the File:Save menu option.

Note that the world file format has changed significantly from
previous versions. The script tools/worldfileconv.tcl will
attempt to convert your old (pre Stage-1.2) world files to the new
format.

The worldfile is given as the last argument when invoking Stage: $ stage <worldfile>.
Stage searches for the specified file in these directories, in this order:

the current directory

the directory that contains the current world file

the directories listed in the STAGEPATH environment variable

STAGEPATH works like the PATH variable of most shells. It is a list of directories to be searched, separated by colons. An example of how to set STAGEPATH in the BASH shell: